Gross Cary P, Mallory Raburn, Heiat Asefeh, Krumholz Harlan M
Yale University School of Medicine, Yale-New Haven Hospital Center for Outcomes Research and Evaluation, PO Box 208025, 333 Cedar Street, New Haven, Connecticut 06520, USA.
Ann Intern Med. 2002 Jul 2;137(1):10-6. doi: 10.7326/0003-4819-137-1-200207020-00007.
A common criticism of randomized, controlled trials (RCTs) is that the enrollment process may be highly selective and those who enroll may not represent persons in the general population. The recruitment process reported in published RCTs has not been systematically evaluated.
To determine whether published RCTs report information about how their study sample was assembled and to describe the proportion of potential study participants who were actually enrolled.
Cross-sectional explicit review of RCTs published in four high-impact medical journals between 1 April 1999 and 1 April 2000. All RCTs involved interventions in humans.
The number of persons who were screened for eligibility, the number who were eligible, and the number who were enrolled in each RCT.
A total of 172 RCTs were reviewed. Ninety (52%) reported the number of persons who were evaluated by the investigators for eligibility, and 74 (43%) reported the number of persons who were actually eligible for participation. Of the studies that reported quantitative recruitment information, the median proportion of screened persons who were eligible for participation was 65% (interquartile range, 41% to 82%) and the median proportion of eligible persons who enrolled was 93% (interquartile range, 79% to 100%). Some trials reportedly enrolled every person screened for eligibility; others screened as many as 68 people for each person finally enrolled.
Many RCTs published in major medical journals do not provide information about the patient recruitment process. As a result, it is difficult for readers to gauge the extent to which participants may represent a highly selected subgroup.
对随机对照试验（RCT）的一个常见批评是，入组过程可能具有高度选择性，入组的人可能不代表普通人群。已发表的随机对照试验中所报告的招募过程尚未得到系统评估。
确定已发表的随机对照试验是否报告了有关其研究样本如何选取的信息，并描述实际入组的潜在研究参与者的比例。
对1999年4月1日至2000年4月1日期间在四种高影响力医学期刊上发表的随机对照试验进行横断面明确回顾。所有随机对照试验均涉及对人类的干预。
每个随机对照试验中接受资格筛查的人数、符合资格的人数以及入组的人数。
共回顾了172项随机对照试验。90项（52%）报告了研究者评估资格的人数，74项（43%）报告了实际符合参与资格的人数。在报告了定量招募信息的研究中，符合参与资格的筛查者的中位数比例为65%（四分位间距，41%至82%），符合资格并入组者的中位数比例为93%（四分位间距，79%至100%）。据报道，一些试验让每个接受资格筛查的人都入组；另一些试验每最终入组一人要筛查多达68人。
在主要医学期刊上发表的许多随机对照试验未提供有关患者招募过程的信息。因此，读者很难判断参与者在多大程度上可能代表一个经过高度挑选的亚组。
